package com.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.reggie.common.BaseContext;
import com.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
@WebFilter(filterName = "LoginCheckFilter",urlPatterns = "/*")   //过滤器注解  filterName过滤器名称   urlPatterns路径 拦截所有请求
public class LoginCheckFilter implements Filter {

    //路径匹配器，匹配通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;

        //定义需要放行的请求和静态资源   但匹配不了通配符**所以需要借助上面的路径匹配器
        String[] urls = new String[]{
            "/employee/login",
            "/employee/logout",
            "/backend/**",
            "/front/**",
            "/common/**",
            "/user/login",
            "/user/sendMsg"
        };

        //1.获取请求路径
        String requestURI = request.getRequestURI();


        //2.判断本次请求是否需要处理
        boolean check = check(urls,requestURI);

        //3.如果不需要处理，则直接放行
        if(check){
//            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4.1需要处理 判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("employee")!=null){
            log.info("用户已登录，用户id为{}",request.getSession().getAttribute("employee"));
            //将用户id存入ThreadLocal中
            Long empId = (Long)request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request,response);
            return;
        }


        //4.2需要处理 判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user")!=null){
            log.info("用户已登录，用户id为{}",request.getSession().getAttribute("user"));
            //将用户id存入ThreadLocal中
            Long userId = (Long)request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);
            filterChain.doFilter(request,response);
            return;
        }


        log.info("用户未登录");
        //5.访问的不是公共资源，且没有登录  前端有响应拦截器 通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));   //NOTLOGIN是前端要接收的放回登录页面的固定值

    }

    /**
     * 路径匹配  检查本次请求是否需要放行
     * 是否为静态资源 是则返回true  不是则返回false
     * @param urls
     * @param requestURI
     * @return
     */
    public  boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);   //值为true 表示匹配上了
            if(match){
                return true;
            }
        }
        return false;
    }



}
